EP0328557B1

EP0328557B1 - Hitch assembly and method

Info

Publication number: EP0328557B1
Application number: EP87907856A
Authority: EP
Inventors: Andrew Peter Blau; Joseph Anthony Masso
Original assignee: Caterpillar Industrial Inc
Current assignee: Caterpillar Industrial Inc
Priority date: 1987-08-18
Filing date: 1987-10-19
Publication date: 1992-03-04
Anticipated expiration: 2007-10-19
Also published as: WO1989001418A1; JPH02500186A; AU8320787A; EP0328557A1; DE3777197D1; KR890701382A; US4807714A

Abstract

A hitch assembly (22) and method for connecting a vehicle (10) to a towed apparatus (16) and releasing the towed apparatus (16) from connection to the underlying supporting surface (20) has a tongue (24) which is connected to the towed apparatus (16) and a socket engaging device (44) mounted on the vehicle (10). The socket engaging device is movable from a first position (46) at which the tongue (24) is free form connection to the vehicle (10) to a second position (48) elevationally spaced from the first position (46) at which the tongue (24) is connected to the socket engaging device (44). An actuator (92) which is mounted on the vehicle (10) and connected to the socket engaging device (44) elevationally moves the socket engaging device between the first and second positions (46, 48). A tongue supporting member (74) is movable from a surface supported position (73) to a socket engaging device supported position (75) spaced from the underlying surface (20) in response to movement of the socket engaging device (44) from the first position (46) to the second position (48). The hitch assembly is particularly suited for connecting an automatic guided vehicle (10) to a trailer (16).

Description

This invention relates to a hitch assembly and method of connecting a towed apparatus to a vehicle, and more particularly to a trailer having a tongue, a socket member and a tongue supporting member, and a vehicle having a socket engaging device which is elevationally movable for connecting the socket member to the vehicle and raising the tongue supporting member from a tongue supporting position.
Hitch assemblies for connecting a drawn member, for example, a trailer, implement, and the like to a vehicle, for example, a driverless automatic guided vehicle, a tow vehicle, tractor, and the like have been known for some time. An example of a hitch for connecting an implement to a farm tractor is disclosed in US-A-2 844 390. This patent teaches a connecting member mounted on the implement and a hitch mounted on the tractor. The connecting member has an integral coupling ring and a leg which is pivotally mounted to the connecting member. The leg being pivotally mounted on the connecting member enables the leg to be moved from a ground engaging position to a position at which the leg is free from engagement with the ground. This hitch includes a pin which is elevationally moveable in a downward direction to impale the coupling ring which couples the implement to the tractor. The pin is spring biased in the downward direction and moves downwardly in response to release of a pin lock. The hitch also has upper and lower guide ramps which are flared rearwardly and outwardly to aid in positioning of the coupling ring relative to the pin so that alignment between the two may be achieved. Movement of the coupling ring relative to the pin in a direction toward the pin results in engagement between the lower ramp and the leg. Continuous movement of the coupling in a direction toward the ramp will result in pivotal movement of the leg and disengagement of the leg from the ground. The hitch of the above mentioned patent discloses several problems which this invention is intended to overcome in a simple and economical manner.
One problem is related to pivotal movement of the leg. In order for the connecting member to be aligned with the pin, the leg must be forced by the lower guide ramp to pivot away from engagement with the ground to an elevated position. Friction forces between the ground and the leg may be higher than the forces required to move the implement which will result in rolling of the implement and forcing the leg to pivot in the wrong direction. This, of course, would over stress the leg and cause bending of the leg and failure of the pivot joint between the leg and the connecting member. Also, this excessive force would result in damage to the lower guide ramp. Also, if the leg should extend a distance beneath the upper surface of the ground and become caught the potential for failure of the leg due to over stressing is an even greater possibility.
As the coupling ring moves toward the pin and the leg pivots away from an upright supporting position, the coupling ring will lower into engagement with the lower ramp. As a result, the coupling ring will be supported on the ramp and the entire tongue weight of the towed apparatus will be transferred to the ramp. In order for the coupling ring to be moved into alignment with the pin, the ring will have to slide along the ramp a substantial distance. This sliding movement will cause premature wear of the ramp and coupling ring which will eventually result in premature failure of one or the other. Therefore, it would be advantageous to eliminate this tongue weight carrying sliding motion during coupling ring alignment.
Because the pin is biased by a spring in a downward direction to engage the coupling ring, there is a potential for failure of the spring which would result in an inability to positively retain the pin in engagement with the coupling ring which would result in inadvertent release of the towed implement from connection to the tractor. This is especially true in applications where the underlying terrain is rough and excessive bouncing and pitching of the vehicle and implement occur. Therefore, it would be advantageous to provide a hitch which was positive and did not rely on springs to maintain the hitch in the ring engaged position.
Further, the pin of the subject patent utilizes a cam which is manually actuated to release the pin from connection with the coupling ring and to reset a latch to retain the pin in the raised and unconnected position. Therefore, manpower must be available and on hand each time the towed apparatus is to be released from connection with the tractor. This, of course, is costly and a waste of human resources.
US-A-4,368,899, discloses an automatic hitch mechanism which permits powered actuation of a pivotally mounted hook member which permits coupling and uncoupling of the hook member with a towed implement. Since the hook member pivots in order to engage the latch ring mounted on the implement, undesirable translation of the implement along the ground will take place which is not acceptable in industrial applications where accurate positioning of the towed trailer and the like is required.
US-A-3150609 discloses a hitch assembly for connecting a vehicle to a towed apparatus supported on an underlying supporting surface, the hitch assembly comprising a tongue having first and second spaced apart end portions and being connected at the first end portion to one of the vehicle and towed apparatus; a socket member connected to the second end portion of the tongue; a socket engaging device having a guide and a hooking member, the guide being mounted on the other of the vehicle and towed apparatus and defining an upwardly and downwardly oriented guide path, the hooking member having a guide following portion which follows the guide so that the hooking member is movable upwards and downwards along the guide path between a first position, at which the hooking member is free from connection with the socket member, and a second position at which the hooking member is engagable with and connected to the socket member; a first flange member connected to the other of the vehicle and towed apparatus adjacent to the hooking member at a location at its second position, the socket member being capturable between the hooking member and the first flange member at the second position of the hooking member; and an actuator having a movable output member connected to the hooking member so that the hooking member is movable between the first and second positions in response to movement of the actuator output member; and according to a primary aspect of the present invention, such an assembly is characterised by the tongue being connected at its first end portion to the towed apparatus; and by a tongue supporting member having spaced apart mounting and piloting end portions and being connected at the mounting end portion to the tongue, the tongue supporting member extending downwards from the tongue and being arranged to engage at its piloting end portion in respective pilot apertures provided in the underlying supporting surface; the tongue being raisable from a surface supported position, at which the piloting end portion of the tongue supporting member is engaged, in use, with a pilot aperture to a socket engaging device supported position, at which the piloting end portion of the tongue supporting member is disengaged from the pilot aperture in response to raising of the hooking member from the first position towards the second position to capture the socket member and raise the tongue.
The invention also includes an industrial transportation system, comprising a driverless automatic guided computer controlled vehicle having a frame and a plurality of wheels rotatably connected to the frame, engaged with an underlying supporting surface; and connected to an industrial trailer by a hitch assembly according to the primary aspect of the invention, the industrial trailer forming the towed apparatus and having a plurality of wheels engaged with the underlying supporting surface, wherein the underlying supporting surface has a plurality of spaced apart ones of the pilot apertures disposed therein defining a plurality of docking locations.
In the accompanying drawings:

Fig. 1 is a diagrammatic side elevational view of an embodiment of the present invention showing a vehicle connected to a towed apparatus by a hitch assembly.
Fig. 2 is a diagrammatic enlargened partial side elevational view of the hitch assembly of Fig. 1 showing the towed apparatus connected tongue in an elevated position, a socket engaging device at a second position at which the socket engaging device is engaged with and connected to a socket member, and a tongue supporting member elevationally spaced from being disposed in a pilot aperture in an underlying supporting surface;
Fig. 3 is a side elevational view of the hitch assembly of Fig. 1 showing the socket engaging member at a first position at which the socket engaging member is free from engagement with the socket member and the tongue supporting member disposed in the pilot aperture of the underlying supporting surface;
Fig. 4 is a diagrammatic top elevational view of Fig. 3 showing the hitch assembly in greater detail;
Fig. 5 is a diagrammatic side elevational view of a alternate embodiment of the hitch assembly of Fig. 1 showing the tongue at a first position at which the socket engaging member is free from connection with the socket and the tongue supporting member is disposed in the pilot bore of the underlying supporting surface;
Fig. 6 is a diagrammatic side elevational view of the alternate embodiment of Fig. 5 showing the socket engaging member disposed in connection with the socket member and the tongue supporting member elevationally spaced from being disposed in the pilot bore of the underlying support surface; and
Fig. 7 is a top elevational view of the alternate embodiment of Fig. 5 showing the construction of the hitch assembly in greater detail.

With reference to the drawings, and particularly Fig. 1, a vehicle 10 having a frame 12 and a plurality of wheels 14 rotatably connected to frame 12 is provided for towing a towed apparatus 16 having a plurality of rotatably mounted wheels 18 (only one shown) over an underlying supporting surface 20. The vehicle 10 is preferably a driverless automatic guided computer controlled vehicle 10 which has free ranging capabilities. However, other types of vehicles, for example, tuggers, tractors, fork lifts, and the like which have the ability to tow a payload are contemplated and within the scope of this invention. The towed apparatus 16 is preferably an industrial trailer, however, other types of towed apparatuses, such as, earthworking implements, and the like are contemplated and within the scope of this invention. A hitch assembly 22 is provided for connecting the vehicle 10 to the towed apparatus 16 which is supported on the underlying supporting surface 20. In applications such as industrial transportation systems 23 wherein the vehicle 10 is automatically guided, control devices (not shown) will be provided to sequentially and automatically connect to the trailer 16 to the vehicle 10. In other applications automatic control may not be required. In either automatic or manual vehicle applications the hitch assembly 22 of the subject invention is applicable for use.
Referring to Figs. 2-4, the preferred embodiment, the hitch assembly 22 has a tongue 24 of an elongate configuration. The tongue 24 has first and second spaced apart end portions 26,28. The first end portion 26 is connected to the trailer 16 and the second end portion 28 is connected to a socket member 30. A bracket 32 having spaced apart sides 34 and 36 is mounted on an end portion 38 of the frame 12. It should be noted that the tongue 24 may be connected to the vehicle and the bracket 32 to the trailer 16 without departing from this invention. The bracket 32 also has first and second substantially parallel spaced apart flange members 40,42 which extend between the first and second side members 34 and 36 of bracket 32 and are connected to the first and second sides 34 and 36 and any suitable manner, such as by welding. The second member 42 preferably extends past the first and second sides 34 and 36 and is fastened at opposite ends to the second end portion 38 of the vehicle frame 12.
A socket engaging device 44 is mounted on the bracket 32 and elevationally movable between a first position 46 (Fig. 3) at which the socket member 30 is free from connection with the socket engaging device 44, and a second position 48 (Fig. 2) elevationally spaced from the first position 46, at which the socket member is engaged with and connected to the socket engaging device 44.
The socket engaging device 44 of the preferred embodiment, as shown in Figs. 1-4, has a guide 49 which is connected to the bracket 32 and defines an elevationally oriented guide path 66. The guide 49 has first and second sleeves 50,52 which are mounted on the first and second flange members, respectively. The sleeves 50,52 each have a bore 54 disposed therein and are elevationally axially aligned with each other. A hooking member 64 having a guide following portion 65 is connected to the guide 49 and movable along the guide path 66 between the first and second positions 46,48. The guide following portion 65 preferably has a shaft 58 is disposed in the bores 54 and 56 and slideably movable in the bores 54,56. First and second bearings 16 and 62 are disposed in the first and second bores 54 and 56 respectively and serve to freely guide the shaft 58 in the bores 54,56.mounted on the shaft 58 and elevationally moveable along an elevationally oriented guide path 66 defined by the axis of the shaft 58 and the first and second sleeves 50 and 52. The hooking member 64 is preferably connected to the shaft 58 by a pin 68 at an annular body portion 69 of the hooking member 64 which is disposed about the shaft. It should be noted that an alternative construction would include fixed connection of the shaft 58 to the sleeves 50 and 52 and slideable movement of the hooking member 64 and particularly the annular body portion 69 along the shaft 58. The hooking member 64 is shown as having a upwardly bent end portion 70 extending from the annular body portion 69. The bent end portion is suited for engaging the socket member 30 and capturing the socket member 30 between the bent end portion 70 and the first flange member 40. It is to be emphasized that configurations other than the bent end portion 70 may be utilized for achieving equivalent end results which sandwich the socket member 30 between the bent end portion 70 and the first flange member 40.
A power means 71 is provided for moving the socket engaging device 44 and particularly the hooking member 64 elevationally along the guide path 66 between the first position 46 at which the hooking member 64 is spaced a preselected elevational distance from the first flange member 40 and the second position 48 at which the hooking member 64 is closely adjacent the first flange member 40. The tongue 24 is elevationally movable from a surface supported position 73 (Fig. 3), at which the piloting end portion 72 of a tongue supporting member 74 is engaged with the underlying supporting surface 20 and the hooking member 64 is free from engagement with the socket member 30, to a socket engaging device supported position 75 (Fig. 2), at which the piloting end portion 72 is elevationally spaced from the underlying supporting surface 20 and the hooking member 64 is disposed in an opening 76 in the socket member 30. The tongue 24 is elevationally movable between the surface supported position 73 and the socket engaging device supported position 75 in response to elevational movement of the hooking member between the first position 46 and the second position 46. It is to be noted that the socket member 30 is disposed between and engaged with the first flange member 40 and hooking member 64 at the second position 48 of the hooking member 64.
The tongue supporting member 74 has a connecting end portion 78 which is affixed to the tongue 24 at a location on the tongue 24 preferably between the first and second end portions 26 and 28. The connecting end portion 78 has a plurality of threads 80 disposed thereabout which are screwthreadably connected to the tongue 24. The piloting end portion 72 has an annularly configured stop member 82 mounted thereon. The stop member 82 engages an upper end surface 84 of a locating member 86 disposed in an aperture 88 in supporting surface 20. As best seen in Fig. 3, the piloting end portion 72 is disposed in a pilot aperture 90 in a locating member 86 and the stop member 82 is in contact with the upper surface 84. A plurality of locating members 86 are provided at various spaced apart locations on the supporting surface 20. Each locating member 86 defines a docking location for the trailer 16. It should be recognized that it would be possible to substitute a pilot aperture in the supporting surface 20 and achieve substantially the same end results. The locating member is particularly suited for use in applications wherein the supporting surface 20 is rough, uneven and the like. The locating member 26 provides a higher degree of accuracy and precisely establishes the distance between the support surface 20 and the socket member 30 so that the hooking member 64 may be consistently positioned elevationally beneath the socket member 30.
The power means 71 has an actuator 92 which has a housing 94 and and output member 96 movably connected to the housing 94. The output member 96 preferably includes an elongate rod slideably connected to the housing 94. A motor 98 which is preferably electric is operatively connected to the output member 96 and suitable for moving the output member 96 relative to the housing 94. The actuator housing 94 is pivotally connected to the bracket 32 by pivot pin 100 and the output member 96 is pivotally connected to a bifurcated portion 101 of the hooking member 64 by pivot pin 102. The socket engaging device 44 is elevationally movable between the first and second positions 46 and 48 in response to movement of the actuator output member 96. As previously mentioned, the tongue 24 is elevationally moveable from the surface supported position 73 at which the piloting end portion 72 of the tongue supporting member 74 is engageable with the underlying supporting surface 20 to the socket engaging device supported position 75 elevationally spaced from the surface supported position 73, at which the piloting end portion 72 of the tongue supporting member 74 is spaced from the underlying supporting surface 20.
Means 104 is provided for maintaining the shaft 58 from rotation in the first and second bores 54 and 56. The means 104 includes a flat 106 on the shaft 58 and a stop tab 108 secured to the first sleeve and in slideable engagement with the flat 106. Other configurations, such as a key and key way and the like are to be considered alternative constructions and within the scope of this invention.
Mounting means 110 is provided for pivotally connecting the first end portion 26 of tongue 24 to the towed apparatus 16 and maintaining the tongue 24 for pivotal elevational movement about a first axis 112. The first axis 112 is preferably oriented normal to the guide path 66 and the direction of the extension of the tongue supporting member 74. Therefore, pivotal movement of the tongue 24 about the first axis 112 will lie in a plain passing through the guide path 66. Preferably the mounting means 110 includes a hinge 114 having a hinge pin 116. The hinge 114 is secured to the first end portion 26 of tongue 24 in any suitable fashion, such as by fasteners 118, and to the towed apparatus 16 in any suitable well known manner such as by fasteners.
A tongue piloting projection 120 is connected to the second end portion 26 of tongue 24 and extends from the tongue 24 in a direction substantially elevationally transverse the tongue 24. A tongue guiding member 122 has an end 124 and a slot 126 opening at the end. The tongue guiding member 122 is mounted on the bracket 32 at a preselected elevational distance from the supporting surface 20 so that the tongue guiding member 122 is elevationally aligned to engage the tongue piloting projection 120 when the tongue supporting member 74 is at the surface supported position 73 (Fig. 3). The tongue piloting projection is disposable in the tongue guiding slot 126, slidably engageable with the tongue guiding member 122 , and adapted to position the socket member 30 in the guide path 66 and in alignment with the socket engaging device 44 in response to movement of the vehicle 10 in a direction toward the trailer 16. The tongue piloting projection 120 has a tapered end portion 127 and the tongue guiding slot 126 has a V-shaped configuration opening at the end 124 of the tongue guiding member 122. The tapered end portion 127 is slideably engaged with the slot 126 and positions the tongue 24 for alignment purposes with the vehicle 10. The tongue guiding member 122 is preferably an extension of the second flange member 42 and extends in a direction substantially normal to the guide path 66.
Referring to the embodiment of Figs. 5-7 the guide 49 has first and second spaced apart parallel elevationally oriented guide rails 128,130 which are mounted on the first and second sides 34 and 36, respectively, bracket 36. The first and second guide rails 128,130 of this embodiment defines the elevationally oriented guide path 66 located therebetween. The hooking member 64 has a guide following portion 65 which has first and second opposed spaced apart notches 132,134 disposed therein an opening at opposite sides 136,138 of the guide following portion. The first and second guide rails 128,130 are disposed in the first and second notches 132,134 respectively, and the guide following portion is movably guided along the guide rails 128, 130 between the first and second elevationally spaced apart positions 46,48. In this embodiment the first position of the socket engaging device 44 is established by the housing 94 of actuator 92 and the position of the output member 96 when retracted fully into the housing 94 and the second position 48 of the socket engaging device is established by the first flange member 40. The hooking member 64 of this embodiment has a conically shaped portion 140 which is disposable in the opening 76 of the socket member 30. The tapered (or conical) shape will aid in alignment during engagement with the socket member 30. The hooking member 64 has a cylindrical projection 142 which is disposable in a receiving aperture 144 in the first flange member 40 at the second position 48 of the socket engaging device 44. It is to be noted that the opening 76 is elongated to reduce the accuracy required in mating engagement of the socket member 30 with the socket engaging device 44.
Because hooking member 64 is pivotally connected to the output member 96 by pin 102 adequate surface contact between the guide following portion 65 and the socket member 30 may be achieved. It should be recognized that when the projection 64 is disposed in the receiving aperture 144 the tongue 24 is securely connected to the hooking member 64 which results in positive connection of the towed apparatus 16 to the frame 12 of vehicle 10. It should be noted that the socket member 30 is disposed in a sandwiched fashion between the first flange member 40 and the guide following portion 65 of the hooking member 64 at the second position 46 of the socket engaging device 44.
The first and second guide rails 128 and 130 guides the hooking member 64 and supports the housing 94 output end orientation. This is achieved through pivotal connection of the output member 96 to the hooking member 64 by pin 100.
The mounting means 110 which connects the first end portion 26 of the tongue 24 of this embodiment to the trailer 16 is slightly different than that of the preferred embodiment. The differences lie in the fact that the trailer 16 has a cutout portion 146 for receiving a portion of the hinge 114 when the tongue 24 is elevated and the socket engaging device 44 is at the second position 48 as shown in Fig. 6. The hinge 114 like that of the other embodiment is pinned to the trailer 16 by hinge pin 116 so that pivotal movement about the hinge pin may take place. As the reader may have observed, pivotal movement of the tongue 24 about hinge pine 116 will result in elevational movement of the tongue supporting member 74 in a plane. The piloting end portion 72 of the tongue supporting member 74 has a tapered portion 148 which assists in positioning the tapered portion in the pilot aperture 90 of the locating member 86. Thus, the tongue supporting member 74 may be easily moved between the surface supported position 73 and the socket engaging device supported position 75.
In this alternate embodiment, the tongue 24 extends at an angle to the underlying supporting surface 20 at the surface supported position 73 (Fig. 5) so that the socket member 30 is at a high enough elevation to be disposed between the hooking member 64 and the first flange member 40. The tongue supporting member 74 however extends from the tongue 24 in an elevational direction similar to that of the preferred embodiment downward to the underlying surface and substantially parallel to the guide path 66 defined by the first and second guide rails 128,130.
As best seen in Fig. 7, the socket member 30 has first and second tapered sides 150,152. These tapered sides 150,152, assist in guiding the tongue 24 into alignment with the socket engaging member 44 so that the socket engaging member 44 may be mated with the socket member 30. The first and second tapered sides 150,152 contact the first and second sides 34, 36 of the bracket, respectively, and force alignment through movement of the vehicle 10. It should be noted that these elements provide alignment in a manner similar to that of the tongue piloting projection 120 and tongue guiding member 122.

Industrial Applicability

With reference to the drawings, the automatic guided vehicle 12 is primarily suited for industrial transportation system applications wherein parts to be machined, stored, and/or assembled are transported within the facility on trailers 16. At various locations within the facility the plurality of pilot apertures 90 disposed in the underlying supporting surface 20 are provided. The plurality of pilot apertures 90 define a plurality of docking locations at which the trailers 16 are deposited and/or picked up. As previously mentioned the purpose of the pilot apertures is to accurately locate the trailers 16 so that the automatic guided vehicle 10 may be dispatched to a specific docking location to acquire the trailer 16.
In operation the automatic guided vehicle 10 is dispatched to a specific docking location to acquire a specific trailer 16 to be transported. Upon arrival at the docking location the onboard computer and vehicle guidance system accurately position the end portion 38 of the vehicle 10 adjacent the towed apparatus 16. The vehicle 10 moves in a direction toward the trailer 16 so that the slot 126 in the tongue member 122 engages the tongue piloting projection 120 and guides the tongue piloting portion to a position at which the socket member 30 is disposed in hooking member receiving alignment with the hooking member 64. The socket engaging device 44, during this maneuver, is at the first position 46 so that the hooking member 64 is elevationally spaced beneath the socket member 30 and within the path 66 of elevational movement of the socket engaging device 44.
Upon completion of this alignment maneuver as determined by the tongue guiding member 122 tongue piloting projection 120. The power means 71 which is connected to the socket engaging device 44 is actuated which causes output member 96 to move and elevationally raise the socket engaging device 44 from the first position 46, along the guide path 66, to the second position 48, at which the socket member 30 is disposed between and in contact with the hooking member 64 and the first flange member 40. At this position the tongue 24 is securely connected to the automatic guided vehicle 10.
As a result of this movement, the tongue 24 pivots about axis 112 of pivoted pin 116 in an upward direction in response to movement of the hooking member 64 from the first position 46 to the second position 48. Pivotal motion of tongue 24 in this direction causes elevational movement of the tongue supporting member 74 from the surface supported position 73 at which the piloting end portion 72 is engaged with the underlying supporting surface 20 and from being disposed in pilot aperture 90 to the socketed engaging device supported position 75 at which the piloting end portion 72 is elevationally spaced from the underlying supporting surface 20 and from engagement in the pilot aperture 90. The trailer 16 is now free to be transported and free from connection to the underlying supporting surface 20 at the socket engaging device supported position 75. Once the tongue supporting member 74 is lifted in this manner the trailer 16 is towed to a preselected deposit location within the facility. It is to be noted that the deposit location may or may not have pilot apertures 90 in the supporting surface 20. The tongue supporting member 74 will serve to support the tongue 24 on the underlying surface 20 and allow disconnection and connection of the trailer 16 to and from the vehicle 10. This is possible since the distance between the underlying surface 20 and socket member 30 is within an acceptable distance range for allowing the hooking member 64 to be positioned beneath when at the first position 46.
Upon arriving at the deposit location the power means 71 is actuated and the output member 96 lowers the socket engaging device 44 along the guide path 66 from the second position 48 to the first position 46 at which the hooking member 64 is freed from connection with the socket member 30 and spaced from being disposed in the opening 76. As the socket engaging device 44 lowers the tongue 24 will follow. The piloting end portion 72 will move in response to pivotal motion of the tongue about axis 112 until the piloting end portion 72 is disposed in pilot aperture 92 and the weight of the tongue 24 is supported by the surface 20. It should be noted that in the embodiments of Fig.s 2-4 the stop member 32 supports the weight of the tongue 24 and in embodiment of Figs. 5-7 the tapered portion 148 supports the weight of the tongue 24 on the underlying surface 20.
Thus, the hitch assembly 22 provides an apparatus and method for simultaneously connecting the trailer 16 to the vehicle 10 and releasing the trailer 16 from connection to the underlying support surface 20 in a simple, economical, and efficient manner.

Claims

1. A hitch assembly (22) for connecting a vehicle (10) to a towed apparatus (16) supported on an underlying supporting surface (20), the hitch assembly (22) comprising a tongue (24) having first and second spaced apart end portions (26,28) and being connected at the first end portion (26) to one of the vehicle (10) and towed apparatus (16); a socket member (30) connected to the second end portion (28) of the tongue (24); a socket engaging device (44) having a guide (49) and a hooking member (64), the guide (49) being mounted on the other of the vehicle (10) and towed apparatus (16) and defining an upwardly and downwardly oriented guide path (66), the hooking member (64) having a guide following portion (65) which follows the guide (49) so that the hooking member is movable upwards and downwards along the guide path (66) between a first position (46), at which the hooking member (64) is free from connection with the socket member (30), and a second position at which the hooking member (64) is engagable with and connected to the socket member (30); a first flange member (40) connected to the other of the vehicle (10) and towed apparatus (16) adjacent to the hooking member at a location at its second position (48), the socket member (30) being capturable between the hooking member (64) and the first flange member (40) at the second position (48) of the hooking member (64); and an actuator (92) having a movable output member (96) connected to the hooking member (64) so that the hooking member is movable between the first (46) and second (48) positions in response to movement of the actuator output member (96); characterised by the tongue (24) being connected at its first end portion (26) to the towed apparatus (16); and by a tongue supporting member (74) having spaced apart mounting and piloting end portions (78,72) and being connected at the mounting end portion (78) to the tongue (24), the tongue supporting member (74) extending downwards from the tongue (24) and being arranged to engage at its piloting end portion in respective pilot apertures (90) provided in the underlying supporting surface; the tongue (24) being raisable from a surface supported position (73), at which the piloting end portion (72) of the tongue supporting member (74) is engaged, in use, with a pilot aperture (90) to a socket engaging device supported position (75), at which the piloting end portion (72) of the tongue supporting member (74) is disengaged from the pilot aperture (90) in response to raising of the hooking member (64) from the first position (46) towards the second position (48) to capture the socket member (30) and raise the tongue (24).

2. A hitch assembly (22) according to claim 1, wherein the guide (49) includes a first sleeve (50) having a bore (54) and being connected to the vehicle (10) at a location adjacent to the first position (46) of the hooking member (64); a second sleeve (52) having a bore (56) and being connected to the vehicle (10) at a location adjacent to the second position (48) of the hooking member (64); and a shaft (58) disposed in the bore (54,56) of the first and second sleeves (50,52) and defining the guide path (66), the hooking member (64) being mounted on the shaft (58).

3. A hitch assembly according to claim 2, wherein the second sleeve (52) is connected to a second flange member (42), the two flange members (40,42) forming part of a bracket (32).

4. A hitch assembly (22) according to claim 2 or claim 3, wherein the shaft (58) is slidably disposed in the first and second sleeve bores (54,56) and there are means (104) for maintaining the shaft (58) from rotation in the first and second bores (54,56).

5. A hitch assembly (22) according to any one of the preceding claims, including an electric motor (98) mounted on a housing (94) of the actuator and drivingly connected to the output member (96), the actuator output member (96) being extensibly movable relatively to the actuator housing (94) and pivotally connected to the hooking member (64), and the actuator housing (94) being pivotally connected to the vehicle (10).

6. A hitch assembly (22) according to any one of the preceding claims, further including mounting means (110) for pivotally connecting the first end portion of the tongue (24) to the towed apparatus (16) and maintaining the tongue (24) for pivotal movement upwards and downwards about a first axis (112).

7. A hitch assembly (22) according to claim 6, wherein the mounting means (110) includes a hinge (114) having a hinge pin (116) and being connected to and between the tongue first end portion (26) and the trailer (16), the hinge pin (116) having a first axis (112) and being axially oriented in a direction substantially normal to the guide path (66), and the tongue (24) being pivotally movable about the hinge pin (116) in response to movement of the hooking member (64) between the first and second positions (46,48).

8. A hitch assembly (22) according to any one of the preceding claims, further comprising a tongue piloting projection (120) connected to the second end portion (28) of the tongue (24) and extending from the tongue (24); a tongue guiding member (122) having an end (124) and a slot (126) opening at the end (124), the tongue guiding member (122) being mounted on the vehicle (10) and arranged to engage the tongue piloting projection (120) at the first position (46) of the hooking member (64), and the tongue piloting guiding projection (120) being disposable in the tongue guiding slot (126), slidably engageable with the tongue guiding member (122), and arranged to position the socket member (30) in lateral alignment with the socket engaging device (44).

9. A hitch assembly (22) according to claim 8, wherein the tongue piloting projection (120) has a tapered end portion (127) and the tongue guiding slot (126) has a "V" shaped configuration.

10. A hitch assembly (22) according to any one of the preceding claims, further including a stop member (82) connected to the piloting end portion (72) of the tongue supporting member (74), the stop member (82) being engageable with a locating member (86) including the pilot aperture (90) at the surface supported position (73) of the tongue (24).

11. A hitch assembly (22) according to any one of the preceding claims, wherein the piloting end portion (72) of the tongue supporting member (74) is tapered.

12. A hitch assembly (22) according to any one of the preceding claims, wherein the connecting end portion (78) of the tongue supporting member (74) is screw threadably connected to the tongue (24), and the tongue supporting member (74) extends normally from the tongue (24).

13. A hitch assembly (22) according to claim 1, wherein the guide (49) comprises a first guide rail (128) connected to the vehicle (10) and oriented upwardly and downwardly; and a second guide rail (130) connected to the vehicle (10) and extending in a direction parallel to the first guide rail (128), the first and second guide rails (128,130) defining the guide path (66).

14. A hitch assembly (22) according to claim 13, wherein a guide following portion (65) has first and second spaced apart notches (132,134) opening in opposite directions, the first guide (128) rail being disposed in the first notch (132) and the second guide rail (130) being disposed in the second notch (134).

15. A hitch assembly (22) according to claim 13 or claim 14, wherein the vehicle (10) has a receiving aperture (144) disposed therein and the hooking member (64) has a projection (142), the hooking member (64) being mounted on a rod and the projection (142) being disposed in the receiving aperture (144) at the second position (48) of the hooking member (64).

16. An industrial transportation system (23), comprising a driverless automatic guided computer controlled vehicle (10) having a frame (12) and a plurality of wheels rotatably connected to the frame (12), engaged with an underlying supporting surface (20); and connected to an industrial trailer by a hitch assembly according to any one of the preceding claims, the industrial trailer (16) forming the towed apparatus and having a plurality of wheels (18) engaged with the underlying supporting surface (20), wherein the underlying supporting surface (20) has a plurality of spaced apart ones of the pilot apertures (90) disposed therein defining a plurality of docking locations.